Turbomachines, such as gas turbine engines, generally include a compressor section, a combustor section and a turbine section. A rotor is typically provided extending axially through the sections of the gas turbine engine and includes structure supporting rotating blades in the compressor and turbine sections. In particular, a portion of the rotor extending through the turbine section comprises a plurality of turbine disks joined together wherein each turbine disk is adapted to support a plurality of turbine blades. Similarly, a portion of the rotor extending through the compressor section comprises a plurality of compressor disks joined together wherein each compressor disk is adapted to support a plurality of compressor blades. The portions of the rotor in the turbine and compressor sections are connected by a torque tube.
In a known construction of the rotor, the turbine disks are joined together by a plurality of spindle bolts extending longitudinally through the turbine disks in the axial direction. The spindle bolts are subjected to stresses which may comprise preload stresses and stresses resulting from thrust, centrifugal force, and/or thermal effects.